Encapsulated terminal board connector



Feb. 15, 1966 D- M. HAEFELE 3,235,829

ENCAPSULATED TERMINAL BOARD CONNECTOR Filed May 29, 1963 Fig./ /2

a0 62 2a /0 5 5% n /51/ 34 Fig. 4 l2 5 40 52 l 56 42 David M. Haefe/e 4 i 1. 46 28 INVENTOR.

United States Patent 3,235,829 ENCAPSULATED TERMINAL BOARD CUNNECTOR David M. Haefele, Dallas, Tex, assignor to Crown Design & Manufacturing Corp., Dallas, Tex., a

corporation of Texas Filed May 29, 1963, Ser. No. 284,207 8 Claims. (Cl. 339-17) The present invention generally relates to an electrical connecting device and more particularly a novel and improved device for electrically connecting the terminals on a conventional terminal block such as employed in the central switching stations of telephone systems. This application is an improvement on the construction shown in copending application Serial No. 154,170, filed November 22, 1961 for Terminal Board Connector, now abandoned.

In the communication field, particularly in telephone systems, one of the problems is the manner in which the various communication lines are interconnected in a central switching station. Conventionally, the incoming lines are connected to terminal blocks, with the lines from the switching equipment also being connected to these blocks so that the blocks function to connect the switching equipment to the accompanying lines. It is wellknown practice to connect various terminals of the block electrically by using jumper wires and it is the orientation of the jumper wires that must be frequently changed for connecting different terminals and the process of removing conventional jumper wires and then reconnecting them to different terminals of the terminal blocks is a tedious and time-consuming process.

It is an object of the present invention to provide a terminal board connector for electrically connecting the terminals of a terminal block with the connector of the present invention replacing the conventional jumper wires with the signals still being routed to the desired location as determined by the particular construction of the connector of the present invention.

Another object of the present invention is to provide a terminal connector which maybe quickly installed or removed without requiring any special tool or any special skill on the part of the operator.

A further object of the present invention is to provide a terminal connector including a plurality of printed circuits thereon which is extremely economical to produce.

Another important feature of the present invention is to provide a terminal board connector having a minimum of parts thus rendering it relatively simple in construction but long-lasting and efficient in operation while being relatively inexpensive to manufacture.

A further important object of the present invention is to provide a terminal board connector having printed circuits therein with the printed circuitry being coated or covered with a transparent high temperature resistant epoxy resin. This eliminates the possibility of the connector being shorted out while work is being done on adjacent terminals. Such shorting can be caused by tools bridging the copper printed circuit or solder splash can also short the circuit. The coating or encapsulation of the printed circuits eliminates the possibility and hazard of shorted circuits.

Still another very important feature of the present invention is to provide novel connector springs attached to the fireproof member which are generally U-shaped in configuration with one leg of the U-shaped spring lying against and being slightly elongated and attached to the fireproof base member or board. by virtue of an eyelet,

together with two dimples being provided in the spring next to the eyelet. These dimples control the spring ten- Patented Feb. 15, 1966 sion due to the fact that connection between the spring opening and the top of the dimples is held to a very precise dimension as the spring is made. This allows the eyelet head to be formed in any manner, even completely flattened, and proper spring tension will be maintained for effective electrical connection with the terminals on the terminal block.

Yet another feature of the present invention is the provision of a number identification system incorporated into the end area of the board with the numbering system being such that the numbers adjacent each edge of the board are inverted in relation to each other so that the unit may be put on either side of the terminal lugs and the identifying number can easily be read thereby enabling the particular printed circuit on the board to be readily identified.

Yet another object of the present invention is to provide a connector having relatively low height which permits work on the adjacent lugs without disrupting customer service and allows wiring to be laid down on a row of blocks without flipping the connector off the lugs. Also, the top of the lugs are used in attaching wire and solder and this is done many times which results in lumps of solder and rough surfaces on the top portion of the lugs. The present structure enables the connector to be installed horizontally thus permitting its installation below the top part of the lug since installation is made at the bottom of the lug where it is usually in good condition.

Another very important feature is the construction of the board from heat-resistant material since this feature also allows workmen to work on adjacent lugs without disrupting customer service, since such work normally employs hot soldering guns or irons which if brought into contact with a non-heat-resistant board would damage the board and cause that particular circuit to be disabled at least temporarily.

Yet another object of the present invention is to provide a terminal connector having a baseboard which may be flexed to a desired orientatio to enable the connector to align with terminal lugs even if the terminal lugs have been misaligned for some reason or other. Also, the particular construction of the spring contact enables contact to be made on both sides of the lug with the two dimples and the spring itself forming a three-point con tact for the circuits. Also, the connector spring of the present invention has a detent extending towards the board for reception in a recess therein for retaining the spring contact in desired orientation in relation to the board. Also, the elongation and construction of the U-shaped spring enables the spring to slightly swing out away from the board to accommodate misaligned or bent lugs on the terminal block. In over-all consideration, the connector of the present invention has many features that enable it to be effectively and efficiently employed for the purposes for which the same is intended.

These together with other objects and advantages which .will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is an end elevational view of a conventional terminal block showing one of the connectors of the present invention installed thereon;

FIGURE -2 is an elevational view of one of the terminal connectors;

FIGURE 3 is a plan view of the construction of FIG- URE 1;

FIGURE 4 is a detailed sectional view, on an enlarged scale, taken substantially upon a plane passing along sec- 3 tion line 4-4 of FIGURE 2 illustrating the structural features and relationship of the spring contact to the mounting board with the components being somewhat exaggerated in configuration;

FIGURE 5 is a transverse, sectional view taken substantially upon a plane passing along section line 55 of FIGURE 4 illustrating further structural details of the invention; and

FIGURE 6 is a perspective view of one of the spring contacts employed in the terminal connector of the present invention.

Referring now specifically to the drawings, the terminal connector of the present invention is generally designated by the numeral 10 and is attached to the terminal lugs 12 on a conventional terminal block 18 which includes a generally rectangular body 20 of insulating material and the terminal block also includes depending terimnal lugs or plates 22 thereon. The construction of the plate 22 is conventional and has notches 24 in their edges for connection with an incoming communication line or conductor 26 in any suitable manner such as by solder or the like. The conductor 26 may be connected to any other suitable structure such as an incoming communication line, or other mechanism in the switching station.

The terminal lugs 12 are electrically connected with the plates 22 thus enabling the various conductors 2-6 to be selectively connected by connecting the upper ends or terminals 12 with jumper Wires in conventional practice. The terminal connector of the present invention is employed to replace the use of terminal wires and the terminal connector 10 includes a generally rectangular base or board 28 constructed of heat resistant fireproof insulating material. The board 28 has rounded corners 30 and is provided with a plurality of spring contacts 32 mounted thereon. There are six spring contacts 32 on the board 28 and each of the spring contacts 32 is electrically connected to one of the six terminal lugs 12. Disposed on one or both ends of the board 28 is an identifying number 34 which extends one-half of the width of the board. Two numbers are disposed in alignment and are inverted in relation to each other so that regardless of which side edge of the board is disposed u-pwardly, the identifying number may be easily read for indicating the particular circuitry on that board.

The board 28 is provided with a plurality of small bores 36 and a plurality of larger bores 38 which are arranged in longitudinally spaced pairs with each pair including one large bore or aperture 38 and one smaller bore or aperture 36. The six spring clips are secured in place with each spring clip being associated with a pair of bores. The spring clip 32 includes an outer leg 40, a connecting bight portion '42 and an elongated inner leg 44 which extends beyond the confines of the outer leg 40 as illustrated in FIGURES 4 and 6. The elongated leg 44 is provided with an aperture 45 for alignment with the larger bore or apertures 38 and for receiving a fastener 46 therethrough in the form of a rivet or eyelet which is riveted over at both the top and bottom ends for securing the spring contacts 32 to the board 28. Spaced from the aperture 38 and adjacent the bight portion 42, the leg 44 of the spring contact 32 is provided with a depending detent 48 which is received normally within the small bore or aperture in the pair for retaining the spring contact 32 in proper orientation in relation to the board 23.

The junctures between the legs 44 and the bight portion 42 is rounded as at 56 and the juncture between the bight portion 42 and the leg 40 is also rounded as at 52 and the leg 40 normally converges towards the leg 44 and has a terminal end flared outwardly as at 54 for providing effective contact with the terminal lug 12 along generally a transverse line of contact. For effectively contacting the opposite surfaces of the lug 12, the leg 44 of the spring contact 32 is provided with a pair of upwardly extending dimples 56 which are spaced transversely from each other and are adjacent the eyelet fastener 46 and disposed slightly longitudinally spaced from the line of contact formed by the outwardly flared end portion 54 of the leg 44. The dimples 56 serve to effectively electrically contact the terminal log and actually form a three-point contact for the circuit and further enabling contact to be made on both sides of the lug, that is, the connector may be associated with the lugs 12 with the board on either side of the lugs.

As illustrated in FIGURE 1, and also FIGURE 3, the construction of the terminal connector enables the connector to be installed horizontally, that is, parallel to the surface of the terminal block 18 by moving the contacts vertically between the lugs and then sliding the connector 10 laterally for bringing the spring contacts 32 into engagement with the lugs. The outer legs 40 are preferably constructed to be of such length so as to fit in the spaces between the lugs 12. This enables adjacent lugs to be more easily worked on and also enables the spring contacts to engage undamaged portions of the lugs since the top of the lugs are used in attaching wire and solder quite often is employed which results in lumps of solder or rough surfaces on the top portions of the lug. By installing the connector below the top ends of the lugs, this roughened area or lump is avoided. Also, the low height of the board permits work on adjacent lugs without disrupting customer service and allows wiring actually to be laid down across a block without removing the connectors off the lugs if desired.

Also, there is a slight upward bow or convexity 58 in the leg 44 of the spring contact 32 which engages the board 28. When the eyelet fastener 46 is inserted, this U-shaped part or leg 44 is pulled down fiat against the board leaving a spring load effect of the eyelet to the circuit and the spring to the board. Also, the connector has a swing-out feature for the spring which allows the spring to swing out and accommodate for bent lugs or misaligned lugs. Further, the board 28 has a thickness and is made in such a manner that the board may flex and accommodate extreme misaligned lugs if desired.

Printed circuits are provided on the surface of the board 28 opposite from the spring contacts 32 and since circuits include printed conductors 60, 62 and 64 and the ends of the printed circuit forming connecting members are enlarged and encircle and are received under the bottom end of the rivets or eyelets 46. The printed circuit members are of a conductive material such as copper or beryllium copper and, of course, the spring contacts 32 are of highly conductive material as are the eyelets 46.

A coating or covering 66 is provided over the back surface of the board 28 for encapsulating the printed circuits 60, 62, and 64. The coating is of heat-resistant material such as epoxy resin and completely encapsulates the printed circuit as well as the eyelet fasteners 46 to prevent shorting of the printed circuit in the event the rear surface of the board 28 is engaged by a conductive member such as a tool, a loose wire or the like and also prevents shorting by solder splashing.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A terminal connector for use in conjunction with a terminal block having a plurality of rows of generally parallel terminal lugs projecting therefrom, said connector comprising an elongated mounting board, a plurality of longitudinally spaced spring contact means mounted on said board, and printed circuit means on said board interconnecting certain of said spring contact means for electrically connecting certain of the terminal lugs when the spring contact means are engaged therewith, said mounting board being constructed of insulating material and having a narrow vertical height whereby the spring contact means may be engaged with the terminal lugs below the upper ends thereof in a horizontal direction thereby enabling the upper end of the lugs to be accessible and also enabling adjacent terminal lugs to be accessible, each of said spring contact means including a generally U-shaped spring member in the form of a flat leaf spring, one leg of said spring being longer than the other and disposed against the surface of the mounting board, fastener means extending through the free end of the longer leg of the U-shaped spring and the board for electrically connecting the printed circuit with the spring contact means, said spring including a shorter leg generally converging towards the longer leg and terminating in an outwardly flared portion thereby forming a contact edge for engaging the terminal lug, said longer leg having a pair of outwardly extending dimples adjacent the end thereof secured to the mounting board for engaging the opposite surface of the terminal lug at two spaced points thereby forming contact with the terminal lugs on both sides thereof.

2. A terminal connector for use in conjunction with a terminal block having a plurality of rows of generally parallel terminal lugs projecting therefrom, said connector comprising an elongated mounting board, a plurality of longitudinally spaced spring contact means mounted on said board, and printed circuit means on said board interconnecting certain of said spring contact means for electrically connecting certain of the terminal lugs when the spring contact means are engaged therewith, said mounting board being constructed of insulating material and having a narrow vertical height whereby the spring contact means may be engaged with the terminal lugs below the upper ends thereof in a horizontal direction thereby enabling the upper end of the lugs to be accessible and also enabling adjacent terminal lugs to be accessible, each of said spring contact means including a generally U-shaped spring member in the form of a flat leaf spring, one leg of said spring being longer than the other and disposed against the surface of the mounting board, fastener means extending through the free end of the longer leg of the U-shaped spring and the board for electrically connecting the printed circuit means with the spring contact means, said spring including a shorter leg generally converging towards the longer leg and terminating in an outwardly flared portion thereby forming a contact edge for engaging the terminal lug, said longer leg having a pair of outwardly extending dimples adjacent the end thereof secured to the mounting board for engaging the opposite surface of the terminal lug at two spaced points thereby fonming contact with the terminal lugs on both sides thereof, said longer leg of said spring including a detent extending towards the mounting board, said mounting board having a small aperture receiving said detent to prevent rotational movement of the spring about the axis of the fastener.

3. The structure as defined in claim 2 wherein said longer leg of said spring is bowed in its center outwardly from the mounting board so that when the fastener means secures the spring to the mounting board, the longer leg will be straightened out thus tensioning the longer ieg and resiliently biasing it against the mounting board.

4. The structure as defined in claim 3 wherein the elongation of the longer leg of the spring enables the spring to swing out slightly from the mounting board thereby accommodating terminal lugs which are offset or misaligned with other terminal lugs.

5. The structure as defined in claim 4 wherein said mounting board is constructed of normally rigid material capable of being deformed laterally thereby enabling the mounting board to accommodate terminal lugs which are offset to a substantial degree.

6. The structure as defined in claim 2 wherein said printed circuit means includes a plurality of printed conductor circuits formed on the surface of said board opposite to the surface having the spring contact means thereon, and a protective insulating coating for said printed circuit means in the form of heat-resistant material thereby preventing accidental shorting between the printed circuits by engagement with a conductive member or by solder splash.

7. The structure as defined in claim 2 wherein said mounting board is provided with identifying indicia adjacent at least one end thereof with the indicia being duplicated at each side edge of the mounting board with one indicia being inverted in relation to each other thereby enabling the indicia to be observed regardless of the orientation of the mounting board in relation to the terminal lugs thereby enabling the connector to be placed on either side of the mounting lugs.

8. A terminal connector for use in conjunction with a terminal block having a plurality of rows of generally parallel terminal lugs projecting therefrom, said connector comprising an elongated mounting board, a plurality of longitudinally spaced spring contact means mounted on said board, and printed circuit means on said board interconnecting certain of said spring contact means for electrically connecting certain of the terminal lugs when the spring contact means are engaged therewith, said mounting board being constructed of insulating material and having a narrow vertical height, said spring contact means having a height less than the height of the terminal lugs, whereby the spring contact means may be engaged with the terminal lugs below the upper ends thereof in a horizontal direction thereby enabling the upper end of the lugs to be accessible and also enabling adjacent terminal lugs to be accessible, each of said spring contact means including a generally U- shaped spring member in the form of a flat leaf spring, one leg of said spring being longer than the other and disposed against the surface of the mounting board, fastener means extending through the free end of the longer leg of the U-shaped spring and the board for electrically connecting the printed circuit with the spring contact means, said spring including a shorter leg generally converging towards the longer leg and terminating in an outwardly flared portion thereby forming a contact edge for engaging the terminal lug, said longer leg having at least one dimple adjacent the end thereof secured to the mounting board for electrically contacting the terminal l-ug.

References Cited by the Examiner UNITED STATES PATENTS 1,913,871 6/1933 Connell et al. 2,695,392 11/1954 Benander 339113 X 2,849,700 8/1958 Perkin 339151 X 2,858,372 10/1958 Kaufman. 3,088,088 4/1963 Reider 339258 X 3,107,414 10/1963 Sterling. 3,138,417 6/1964 Garrett 33917 FOREIGN PATENTS 475,001 11/ 1937 Great Britain.

JOSEPH D. SEERS, Primary Examiner. 

8. A TERMINAL CONNECTOR FOR USE IN CONJUNCTION WITH A TERMINAL BLOCK HAVING A PLURALITY OF ROWS OF GENERALLY PARALLEL TERMINAL LUGS PROJECTING THEREFROM, SAID CONNECTOR COMPRISING AN ELONGATED MOUNTING BOARD, A PLURALITY OF LONGITUDINALLY SPACED SPRING CONTACT MEANS MOUNTED ON SAID BOARD, AND PRINTED CIRCUIT MEANS ON SAID BOARD INTERCONNECTING CERTAIN OF SAID SPRING CONTACT MEANS FOR ELECTRICALLY CONNECTING CERTAIN OF THE TERMINAL LUGS WHEN THE SPRING CONTACT MEANS ARE ENGAGED THEREWITH, SAID MOUNTING BOARD BEING CONSTRUCTED OF INSULATING MATERIAL AND HAVING A NARROW VERTICAL HEIGHT, SAID SPRING CONTACT MEANS HAVING A HEIGHT LESS THAN THE HEIGHT OF THE TERMINAL LUGS, WHEREBY THE SPRING CONTACT MEANS MAY BE ENGAGED WITH THE TERMINAL LUGS BELOW THE UPPER END THEREOF IN A HORIZONTAL DIRECTION THEREBY ENABLING THE UPPER END OF THE LUGS TO BE ACCESSIBLE AND ALSO ANABLING ADJACENT TERMINAL LUGS TO BE ACCESSIBLE, EACH OF SAID SPRING CONTACT MEANS INCLUDING A GENERALLY USHAPED SPRING MEMBER IN THE FORM OF A FLAT LEAF SPRING, ONE OEG OF SAID SPRING BEING LONGER THAN THE OTHER AND DISPOSED AGAINST THE SURFACE OF THE MOUNTING BOARD, FASTENER MEANS EXTENDING THROUGH THE FREE END OF THE LONGER LEG OF THE U-SHAPED SPRING AND THE BOARD FOR ELECTRICALLY CONNECTING THE PRINTED CIRCUIT WITH THE SPRING CONTACT MEANS, SAID SPRING INCLUDING A SHORTER LEG GENERALLY CONVERGING TOWARDS THE LONGER LEG AND TERMINATING IN AN OUTWARDLY FLARED PORTION THEREBY FORMING A CONTACT EDGE FOR ENGAGING THE TERMINAL LUG, SAID LONGER LEG HAVING AT LEAST ONE DIMPLE ADJACENT THE END THEREOF SECURED TO THE MOUNTING BOARD FOR ELECTRICALLY CONTACTING THE TERMINAL LUG. 